Our Health Library information does not replace the advice of a doctor. Please be advised that this information is made available to assist our patients to learn more about their health. Our providers may not see and/or treat all topics found herein. Tuberculosis (TB) is a serious disease caused by a type of bacteria that is spread through the air. TB is easily spread from person to person through coughs or sneezes. TB usually occurs in the lungs. But it can spread to other parts of the body. TB is either active or latent. TB is caused by Mycobacterium tuberculosis. This is a type of slow-growing bacteria. It thrives in parts of the body that are rich in blood and oxygen, such as the lungs. People with latent TB don't have symptoms. Symptoms of active TB may include a cough that brings up thick and sometimes bloody mucus, tiredness, weakness, loss of appetite, weight loss, fever, night sweats, or a fast heartbeat. A few people may have shortness of breath and chest pain. A skin or blood test is used to check for TB. To look for TB in the lungs, doctors test a sample of mucus from the lungs or do a chest X-ray. To find TB that's not in the lungs, doctors may check a tissue sample (biopsy) or do imaging tests. TB is treated with antibiotics to kill the TB bacteria. How many antibiotics are used and how long you'll take them may depend on whether you have active or latent TB. TB can only be cured if you take all the doses of your medicine. TB that's in the lungs can spread when a person who has active TB breathes out air that has the TB bacteria in it. Another person may breathe in the bacteria. Things like coughing can also release even more bacteria. TB that isn't in the lungs can't spread easily to others. Some people are more likely than others to get TB. This includes people who have a weak immune system, have close contact with someone who has active TB, have poor access to health care, or have a substance use disorder. People who travel or live where untreated TB is common are also at risk. TB in the lungs is spread very easily. To avoid getting TB: A TB vaccine is used in parts of the world where the risk of getting TB is higher. But it's almost never used in the United States. People with latent TB don't have symptoms. Symptoms of active TB in the lungs include: These symptoms start gradually and develop over weeks or months. You may have one or two mild symptoms and not know that you have the disease. Symptoms of TB outside the lungs vary widely, depending on which part of the body is infected. For example, back pain can be a symptom of TB in the spine. Or your neck may get swollen when lymph nodes in the neck are infected. TB develops when you breathe TB bacteria into your lungs. The infection usually stays in the lungs. But the bacteria can move through the bloodstream to other parts of the body. The symptoms of the infection depend on the part of the body affected. In a person who has a healthy immune system, the body usually fights the infection by walling off the bacteria into tiny capsules. (These are called tubercles.) This stage is called latent TB. Most people feel fine and don't have symptoms and cannot spread latent TB. A small number of people who have latent TB may develop active TB at some point in their lives. If a person's immune system can't stop the bacteria from growing, the TB is active. If the TB is active, make sure to take all the medicine your doctor tells you to and on schedule to prevent problems. Without treatment, active TB can cause other serious health problems, such as lung damage. Contact your doctor now if you: Follow up with your doctor if you: TB is found by doing a tuberculin skin test. A nurse will inject TB antigen fluid just under your skin. It will cause a small bump that then becomes flat within an hour. If you have TB bacteria in your body, within the next 2 to 3 days you will get a firm, red bump where the needle went into your skin. The test can't tell when you became infected with TB or if it can be spread to others. A blood test also can be done to look for TB. To find TB in the lungs, doctors test a sample of mucus from the lungs to look for TB bacteria. Doctors sometimes do other tests or take a chest X-ray to help find TB in the lungs. To find TB that's not in the lungs, doctors may check a tissue sample (biopsy) or do imaging tests. TB is treated with antibiotics to kill the TB bacteria. These medicines are given to everyone who has TB. This includes infants, children, and people who have a weakened immune system. Before taking any TB medicines, talk with your doctor if you think you are or may be pregnant. TB can only be cured if you take all the doses of your medicine. If you miss doses, or if you stop taking your medicine too soon, your treatment may not work. Or it may have to go on longer. Your doctor will make a treatment plan that includes the types of medicines to take, how much, how often, for how long, and what side effects to watch for and report back to them. You may have directly observed therapy (DOT). This means that a health care worker watches either in person or on a video call (vDOT) when you take your medicine. DOT helps you remember to take your medicine. And it helps you complete your treatment as soon as possible. Surgery is rarely used to treat TB. But it may be used in severe or drug-resistant TB. Home treatment for TB focuses on taking the medicines correctly, taking good care of yourself, and protecting others from infection. Current as of: January 21, 2026 Author: WebMD Ignite Staff Current as of: January 21, 2026 Author: WebMD Ignite Staff Clinical Review Board This information does not replace the advice of a doctor. WebMD Ignite disclaims any warranty or liability for your use of this information. Your use of this information means that you agree to the Terms of Use and Privacy Policy. Learn how we develop our content. To learn more about WebMD Ignite, visit webmdignite.com. © 2024-2026 WebMD Ignite.Tuberculosis (TB)
What is tuberculosis (TB)?
What causes it?
What are the symptoms?
How is it diagnosed?
How is TB treated?
How It Spreads
What Increases Your Risk
Prevention
The TB vaccine
Symptoms
What Happens
When to Call a Doctor
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All WebMD Ignite education is reviewed by a team that includes physicians, nurses, advanced practitioners, registered dieticians, and other healthcare professionals.
All WebMD Ignite education is reviewed by a team that includes physicians, nurses, advanced practitioners, registered dieticians, and other healthcare professionals.
Our Health Library information does not replace the advice of a doctor. Please be advised that this information is made available to assist our patients to learn more about their health. Our providers may not see and/or treat all topics found herein. Current as of: January 21, 2026 Author: WebMD Ignite Staff Clinical Review BoardTuberculosis (TB)
All WebMD Ignite education is reviewed by a team that includes physicians, nurses, advanced practitioners, registered dieticians, and other healthcare professionals.

